[music-dsp] Re: Declipping
arcane at arcanemethods.com
Tue Feb 22 23:08:41 EST 2005
Nigel Redmon wrote:
>> The zero insertion is a distorting process wherein the distortion
>> products all happen to be above the original band limit so that
>> post-filtering it removes them and only them. No?
> OK, but what is the rationale behind distorting the signal in this way?
Only zeros force all the alias components to be outside the
> If you treat the samples as impulses, inserting zeros isn't a
> "technique"--it's just doing the obvious. I can explain the upsampling
> process in a few sentences, using the impulse model, and I think it
> would be pretty hard for you to come up with math that shows that the
> results are flawed.
I don't think it is flawed from an operational standpoint, I
just find it incorrect to think of sampled data as only
having values at the sample points. There is a difference
between what is being represented and the representation
> If you could explain how and why we choose to
> distort the signal--that you view as continuous--with zeros, I'd be
> interested to read it. I'm not saying that you can't come up with one,
> but if it's simpler and more intuitive than my explanation, I'll be
> impressed ;-) (Really, not trying to put you on the spot--just want you
> to think it through.)
Again, we exploit the serendipitous fact that introducing
that particular distortion leaves us with an easy way of
removing what we don't want to be left with what we do want.
Question. If you take the DFT of a sampled impulse response
do you consider the values between the frequency domain
samples to be zero? If not, the domains being duals, why
would one be so considered and the other not be?
"Things should be described as simply as possible, but no
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